Integrated Bonding Flange Support Disk for Prefabricated Shower Tray

ABSTRACT

A combination for plumbing fixtures, particularly tiled floors with drains, is disclosed along with a method for building a tile floor using the combination. An exemplary combination includes a substantially planar shower tray bonding disk on a flooring substrate and surrounded by a prefabricated polymer foam shower tray on the flooring substrate and at the circumference of the bonding disk. The disk includes an interior rim that defines a drain opening and a plurality of slotted openings for permitting mortar to penetrate the disk. The drain opening in the disk can thus be positioned at a drain cut out in the flooring substrate.

RELATED APPLICATIONS

This application is related to copending application Ser. No. ______filed concurrently herewith for “Double Faced Bond Flange Fixture.”

BACKGROUND

The invention relates to a structural piece used in combination withother structural pieces to form the ceramic tile floor of a shower orsimilar bathroom structure.

In wood-frame construction, ceramic tile shower floors are typicallyformed by first putting a moisture barrier over a wooden subfloor afterwhich a mortar bed is sloped to the position of the drain, typicallyreferred to as sloped fill, or “pre-slope.” A waterproof barrier,commonly referred to as a shower pan liner, is subsequently positionedover the sloped mortar bed and fixed to the drain. Conventional showerpan liners are not designed to bond to a substrate or to ceramic orstone tile and thus a second “floating” (non-bonded) mortar bed must beoverlaid to provide a load distribution layer and bonding surface forthe tile. To have sufficient strength, such non-bonded mortar beds forshower floors should have a minimum thickness (typically 1.5 inches) andshould be reinforced with galvanized wire mesh to comply with industrystandard guidelines.

Most such shower floors are sloped, and typically at a value ofone-quarter inch (¼″) per foot. As a result, the position of the drain,the desired slope, and the length of sloped tile, all combine to definea height difference between the drain and the floor's perimeter (e.g., awall, a curb, or a barrier-free entry).

This method of shower floor construction has proven over time to bereliable when properly built, but requires a high degree of tradeknowledge and skill, and takes considerable time.

For a number of reasons, including consumer preferences, a desiredincrease in construction simplicity, and (in some cases) theunavailability of craftsmen who can carry out the conventional methods,the industry is moving toward simplified construction systems andmethods, and toward simpler, cleaner and “open look” interior spaces.One trend is toward low profile shower curbs and toward eliminatingperimeter curbs entirely.

To facilitate these trends, integrated systems have recently beendeveloped that use lighter materials, and simplified installationmethods that make lower profile shower floor construction both possibleand less time-consuming. Much of this progress has been made possiblewith the advent of a new generation of materials that allow each layerof the structure to be bonded to the adjacent layer(s). In some casesthese systems include a prefabricated shower bed tray (typically formedof polymer foam) which is mortar bonded to the subfloor. In somesystems, a mortar bondable waterproofing membrane is fixed to the foamtray with thin set mortar. The tile is then bonded over the membrane,again using thin set mortar. Thus, a typical integrated system couldinclude (in order) substrate/initial mortar layer/shower tray/secondmortar layer/membrane/third mortar layer/tile.

As an additional consideration, the shower tray and its surrounding areamust be flush with one another so that a level layer of tile can beplaced upon it. To the extent that the shower tray is relatively thickat its perimeter, the surrounding areas must likewise be built up tomatch the tray perimeter. At the same time, the physical nature of thepolymer foam tends to establish about one-half inch (0.5″) as theminimum thickness of the foam tray anywhere—including its thinnestportions at the drain.

As a result, the half-inch thickness of the tray at the drain mustincrease toward the perimeter to provide the ¼″ per foot slope. In turn,any area surrounding the tray perimeter must be made thicker to remainflush with the tray perimeter.

Thus, a thinner tray perimeter is desired, but this goal is limited (orin some cases frustrated) by the necessary thickness for the tray at thedrain.

At the position where the shower drain is required, the flooringstructure, including the shower tray and related portions of theintegrated system, must be sufficiently strong to support the drainwhile still allowing the tile to be placed over the nearby foam tray andaround the drain. Conventionally, this has required a relatively thicktray or relatively thick mortar, either of which in turn adds to thethickness of the overall floor structure and affects its relative heightcompared to the remainder of the area. Such additional thickness can bedisadvantageous in many circumstances, including barrier-free showerenclosures (i.e., without any curbing).

In “fitting” a barrier free-construction within the thickness of typicalsubfloor panels, it is relatively easy to recess the subfloor panels inthe footprint of the shower floor such that they are flush with the topsof the floor joists and without damaging those joists. The harder taskis to compensate for the height difference between the recessed subfloorpanels in the footprint of the shower floor and the adjacent subfloor(typically 0.75 inches).

Conventional shower floor constructions, and even the newer “integratedsystems”, are often too tall (e.g., too thick) to “fit” within a¾″-thick subfloor panel. Obtaining a flush, barrier free entry thusrequires one or more of the following options: cutting or notching theframing members (which typically is a building code violation), having avery tall threshold at the entrance to the bathroom as a result ofbuilding up the floor adjacent to the shower floor to make it flush withthe shower floor; ramping up to and around the shower floor; orproviding an “engineered” solution such as cutting and heading off thejoists in the area of the shower floor and subsequently lowering thesubfloor/framing structure in the area of the shower floor. Suchengineered solutions require extensive work, are costly and, in mostcases, must be included in the design phase of the house. For practicalreasons, this excludes most remodels and retrofits.

As a result, conventional shower floor constructions, including thenewer “integrated systems” are taller (thicker) to provide support forthe assembly or, in the case of the newer “integrated systems,” thedrain.

SUMMARY

In one aspect, the invention is a combination for plumbing fixtures thatincludes a substantially planar shower tray bonding element and aprefabricated foam shower tray surrounding the planar bonding element atthe perimeter of the bonding element.

In another aspect, the invention is a combination for plumbing fixturesthat includes a substantially planar shower tray bonding disk on aflooring substrate and surrounded by a prefabricated polymer foam showertray on the flooring substrate and at the circumference of the bondingdisk. The disk includes an interior rim that defines a drain opening anda plurality of slotted openings for permitting mortar to penetrate thedisk. The drain opening in the disk is positioned at a drain cutout inthe flooring substrate.

In yet another aspect, the invention is a method of building a tiledfloor with a drain. The method includes the steps of positioning asubstantially planar shower tray bonding element that defines a drainopening over a drain cutout in a flooring substrate, mortaring theplanar shower tray bonding element in position over the drain openingcutout, and positioning a polymer foam shower tray on the same flooringsubstrate and in surrounding relationship to the perimeter of the planarshower tray bonding element.

The foregoing and other objects and advantages of the invention and themanner in which the same are accomplished will become clearer based onthe following detailed description taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the shower tray bonding disk of theinvention in the context of a foam shower tray and a curb.

FIG. 2 is a top plan view of the shower tray bonding disk.

FIG. 3 is another perspective view of the shower tray bonding diskpositioned with a shower tray.

FIG. 4 is an environmental perspective view of portions of a showerconstruction.

FIG. 5 is the same environmental view as FIG. 4, but with the addedlower subfloor portion (substrate).

FIG. 6 is the same environmental perspective view as FIGS. 4 and 5, withthe addition of the tile base material on a portion of the substrate.

FIG. 7 is another progressive view in the sequence of FIGS. 4-6 andillustrates the shower tray bonding disk in position over the plumbing.

FIG. 8 is a perspective view of the shower tray bonding disk in positionwith a foam shower tray and a drain flange.

DETAILED DESCRIPTION

The bonding flange support disk of the present invention provides areliable way to provide solid support for a drain in relatively thinassemblies, such as barrier-free shower installations in wood-frameconstruction while compensating for the difference (typically ¾″)between the recessed subfloor of the shower footprint and the adjacentsubfloor.

For purposes of illustration and clarity, the invention herein isdescribed in terms of a floor for a bathroom shower. The skilled personwill recognize, however, that the invention has advantages with respectto other barrier free enclosures where additional thickness in the floorstructure can be disadvantageous.

FIG. 1 is a perspective view of the shower tray bonding element 20 whichin exemplary embodiments is in the shape of a disk. The disk 20 ispositioned in context in combination with a foam shower tray 21 andadjacent a shower curb 22. The disk shape is a convenient design choicerather than an absolute requirement. In the illustrated embodiment, andas is common for ease of installation in some circumstances, the foamshower tray 21 is formed of two portions connected by a joint 23. Asthose familiar with such installations are well aware, the two-partconstruction helps permit the foam shower tray to be positioned on thesubstrate after a drain fixture is already in place.

FIG. 2 is a top plan view of the shower tray bonding disk 20. The disk20 defines a circumferential perimeter 24 and an interior rim 26 definesa drain opening 25. In the illustrated embodiment, the rim 26 isattached to the remainder of the shower tray bonding disk 20 by aplurality of ribs 27. For purposes of allowing thin set mortar topenetrate, the shower tray bonding disk 20 includes a plurality ofslotted openings 30. In the illustrated embodiment, these include aplurality of arc-shaped slots and a plurality of rectangular slots, butagain these shapes are preferred choices rather than limitations.

In particular, when the disk 20 is in position with a drain flange(e.g., 45 in FIG. 8), thin set mortar can easily be pushed into theopenings 30 from the top surface to complete fill those openings. Whenthe drain flange 45 is pressed in from the top, the mortar forms aboundary area between the bottom surface of the drain flange and thesubfloor 41 to provide optimal bonding. Within the openings 30, themortar forms vertical columns that are capable of supporting highcompressive loads. Additionally, any mortar shrinkage is controlled bythe width of the disk cell openings 30. In comparison, if thin setmortar alone were supporting the drain, normal mortar shrinkage wouldoccur primarily in a vertical direction potentially causing the drain totilt from a desired horizontal position. Using the invention, the disk20 helps keep the drain in its set position and limits any mortarshrinkage to minimal lateral amounts within the openings 30. Thus,although thin set mortar does not bond to the disk material per se, themortar can bond through the disk 20 to both the bottom of the drainflange 45 and the subfloor 41.

As background, “thin set mortar” refers to mortars that can be appliedand that will function in their intended manner in thickness on theorder of 0.25 inches (about 5 mm). In addition to the traditionalcombination of water, Portland cement, lime and sand, thin set mortartypically includes a polymer added as an additional component thatincreases the adhesion, toughness, flexibility, tensile strength, andchemical resistance of the overall composition. Representative polymeradditives include ethylene vinyl acetates, polyvinyl alcohol, andvarious latex or epoxy compositions.

In the illustrated embodiment, the disk 20 includes raised portions 31into which a drain flange can nest; e.g. element 45 in FIG. 8. Theraised portions 31 also carry clock marks 28 that form a positioningsystem for the drain flange 45 (FIG. 8). The clock marks help positionthe drain opening either perpendicular or parallel to any adjacent wallso that tile can surround the drain while still being aligned with thewalls.

The disk 20 can be formed of any material that has the requiredstructural strength and that will avoid adverse reactions with any ofthe other materials typically used in shower construction; e.g. the thinset mortar, the polymer tray, or the membranes (where used). For anumber of reasons, including strength, weight, and ease of manufacture,plastics (polymers) are quite effective and an appropriate plastic canbe selected by persons skilled in the art without undue experimentation.Thermoplastic polymers suitable for injection molding tend to beconvenient, relatively inexpensive, and widely available. Typicalchoices include (but are not limited to) acrylic, nylon, polyethylene,polypropylene, polystyrene, polyvinyl chloride, PTFE, polyester,polycarbonate, polyurethane and acrylolnitrile butadiene styrene (ABS).

FIG. 3 is another perspective view of the shower tray bonding disk againin the context of the shower tray 21 and the joint 23 defining the twoportions of the tray 21. In typical modern shower construction, theshower tray 21 is formed of polymer foam with expanded polystyrene foambeing one useful (but not limiting) choice. Polymer foams are typicallymade by adding a blowing agent and a nucleating agent to a polymer meltand then using the blowing and nucleating agents to generate the foam.In the context of a tile floor, the foam should be rigid (rather thancompressible) and can be “closed cell” or “open cell.” Accordingly theskilled person can select the foam and the foaming method on that basisand without undue experimentation. Polyurethane is another exemplarypolymer often used to foam closed cell rigid foams.

The environmental views of FIGS. 4-8 illustrate some of the specificadvantages of the invention. FIG. 4 is a perspective illustration of arelatively typical modern construction of the floor of the shower andits associated plumbing. FIG. 4 illustrates a lower base substrate 32underneath an engineered wood joist 33. These structural elements arealso referred to as an “I-joist” or an I-beam. The joist 33 is formedfrom a web 34 and respective flanges 35 and 36. The substrate 32 doesnot need to be load-bearing and in some circumstances can be theplasterboard ceiling of the next lower floor.

In general, such engineered wood joists have superior strength inrelation to their size and weight, and can carry heavier loads with lesslumber then a dimensional solid wood joist. Such engineered joists arebecoming more common in new constriction and tend to eliminate problems(e.g., bowing, crowning, twisting, cupping, checking, splitting)associated with solid lumber joists. Such joists also have little or noshrinkage. Both the web and the flange can be formed from laminatedveneer, plywood, or oriented strand board.

In order to maintain its integrity, properties and advantages, however,an engineered wood joist must be kept intact. As a result, trimming orcutting into the joist to provide or ease access to plumbing fixturescan have serious consequences and violates relevant building codes inmost jurisdictions. As the figures illustrate, the invention helps theplumber or tile contractor (or both) reduce the difficulty andcomplexity of their tasks while keeping the joists intact.

The I-beam (and typically a plurality of I-beams) 33 carries a showersubfloor or substrate 37. A portion of plumbing 40 is likewiseillustrated adjacent the joist 33 and between the shower subfloor 37 andthe lower substrate 32. As the skilled person will appreciate, one ofthe advantages of the described structural systems is the capability toattach a fixture (e.g., a drain) to existing plumbing relatively easilywhile thereafter being aligned with tile that is not yet laid when thefixture is installed.

A typical structure will also include smaller joists 38 perpendicular tothe engineered joist(s) 33. These smaller joists 38 are carried byhangers 42 that are fixed to the web 34 of the engineered joist 33 alongwith one or more reinforcing panels 39. For purposes of illustrating theoverall construction, the reinforcing panels 39 are shown extendingpartially along the web 34. In most circumstances, however, one or moreof the panels 39 will extend completely along and over the web 34.

FIG. 5 illustrates the same structure environment, but with the additionof a lowered subfloor portion 41. The lowered subfloor portion 41 isattached to and supported by the engineered joists 33 and theperpendicular joists 38. The lowered subfloor portion 41 also includes acut out portion 43 for the eventual drain.

FIG. 6 is the same environmental view as FIGS. 4 and 5, but showing theadditional presence of a tile base layer 44 on the subfloor 37.

FIG. 7 is another identical view, but with the addition (in partialcross sectional and partial perspective manner) of the shower traybonding disk 20 in position surrounding the drain cut out 43 and on thelower subfloor portion 41.

FIG. 8 illustrates a completed structure with the exception of the finallayer of tile and the drain hardware. In particular, FIG. 8 illustratesa drain flange fixture 45 resting on the shower tray bonding disk 20. Inexemplary embodiments, the raised portion 31 on the shower tray bondingdisk 20 conform to the size and shape of the drain flange fixture 45. Asa result, the drain flange fixture 45 can be quickly and easilypositioned on the disk 20.

In the illustrated embodiment, the drain flange fixture 45 includes adepending nipple structure 48 that provides an easy connection to theplumbing 40. Basic pipe connections are well within the knowledge of theskilled person. Basically, the depending nipple 48 can be threaded orunthreaded and can accordingly be joined to the remainder of theplumbing 40 with a coupling or a threaded bushing or a slip threadedbushing (including reducing versions of any of these).

FIG. 8 also shows the foam shower tray 21 in position adjacent theshower tray bonding disk 20 and likewise adjacent the remainder of thetile base layer 44.

FIG. 8 also illustrates that the foam shower tray is inclined from theentry position (designated at 46) entry to the drain and from thelateral portion (designated at 47) to the drain. As a fundamentaladvantage of the invention, the shower tray bonding disk 20 providesadditional structural stability at the drain. Without the shower traybonding disk, the foam shower tray 21 would have to be thicker at thedrain which in turn would require the tray to be even thicker at theboth the entry position 46 and along the lateral portion 47 in order toprovide the necessary incline from the edge to the drain. With theshower tray bonding disk 20 in place, the foam shower tray 21 can bethinner at all points, and thus thinner at both the entry position 46and along the lateral portion 47.

Additionally, in the absence of the shower tray bonding disk 20 of theinvention, the grout or mortar or both would have to be thicker at thedrain fixture to support it.

The shower tray disk 20 provides an overall ease of construction usingthe foam shower tray system and likewise adds structural andconstruction convenience for both zero depth entry floors as well asshower floors that incorporate curbs.

As a result, in another aspect, the invention is a method of building atiled floor with a drain. In this aspect, the method can includepositioning a substantially planar shower tray bonding element thatdefines a drain opening over a drain cutout in a flooring substrate,mortaring the planar shower tray bonding element in position over thedrain opening cutout, and positioning a polymer foam shower tray on thesame flooring substrate and in surrounding relationship to the perimeterof the planar shower tray bonding element.

The method can also include the steps of mortaring the bonding elementand the shower tray in position using thin set mortar.

The method can further include inserting a drain bond flange fixtureinto the drain cutout and over the planar bonding element with portionsof the bond flange fixture overlying portions of the planar bondingelement surrounding the drain cutout in the flooring substrate.

As a final or near final step, the method can include laying a tilefloor over the foam tray and portions of the bond flange fixture.

In many circumstances, particularly using such integrated materials andtechniques, the method can include adding a waterproofing membrane tothe structural combination. In many cases the membrane is positionedover the foam tray before laying the tile floor. Membranes are availablein sheet form, typically as variations of nonwoven fabrics. Examplesinclude KERDI (Schulter Systems, L. P., Plattsburgh, N.Y. 12901), DUROCK(USG Corporation, Chicago, Ill. 60661) and TRUGARD™ (Truco Solutions,LLC, Alpharetta Ga. 30009). Alternatively, membranes can be applied asviscous liquids, suspensions or slurries that cure into the desiredwaterproofing layer. Examples include HYDRO BAN® (LacticreteInternational Inc., Bethany, Conn. 06524) and REDGARD® (Custom Buildingproduces, Inc., Seal Beach, Calif. 90740).

Finally (although not necessarily the final construction step), themethod includes connecting the drain bond flange fixture to a drain pipebelow the flooring substrate.

In the drawings and specification there have been set forth exemplaryembodiments of the invention, and although specific terms have beenemployed, they are used in a generic and descriptive sense only and notfor purposes of limitation, the scope of the invention being defined inthe claims.

1. A combination for plumbing fixtures comprising: a substantiallyplanar shower tray bonding element; and a prefabricated foam shower traysurrounding said planar bonding element at the perimeter of said bondingelement.
 2. A combination for plumbing fixtures according to claim 1wherein said shower tray bonding element defines a drain opening.
 3. Acombination for plumbing fixtures according to claim 1 wherein: saidshower tray bonding element is a circular disk; and said foam showertray defines a circular opening corresponding to the circumference ofsaid disk.
 4. A combination for plumbing fixtures according to claim 2wherein said planar bonding element includes an interior rim thatdefines said drain opening.
 5. A combination for plumbing fixturesaccording to claim 1 wherein said planar bonding element includes aplurality of slotted openings.
 6. A combination for plumbing fixturesaccording to claim 1 wherein said planar bonding element comprises aplurality of raised portions for fixing the position of additionalstructural elements on said bonding element.
 7. A combination forplumbing fixtures according to claim 1 wherein said prefabricated foamshower tray comprises a polymer selected from polystyrene andpolyurethane.
 8. A combination for plumbing fixtures according to claim6 further comprising a bonding flange fixture resting in said bondingelement at a position defined by said raised portions.
 9. A combinationfor plumbing fixtures according to claim 6 further comprising clockmarks on said raised portions for orienting said disk in a desiredposition.
 10. A combination for plumbing fixtures comprising: asubstantially planar shower tray bonding disk on a flooring substrateand surrounded by a prefabricated polymer foam shower tray on saidflooring substrate and at the circumference of said bonding disk; saiddisk including an interior rim that defines a drain opening and aplurality of slotted openings for permitting mortar to penetrate thedisk; and said drain opening in said disk being positioned at a draincutout in said flooring substrate.
 11. A combination for plumbingfixtures according to claim 10 further comprising a drain bond flangefixture resting on said disk and in said drain opening.
 12. Acombination according to claim 11 further comprising: a plumbing drainpipe beneath said drain cutout; and a connection between said bondingflange fixture and said plumbing drain pipe.
 13. A combination accordingto claim 12 wherein said connector comprises a depending connector onsaid bonding flange and a receiving connector on said drain pipe.
 14. Acombination according to claim 13 wherein said depending connector is athreaded nipple and said receiving connector is selected from the groupconsisting of slip threaded bushings and threaded bushings.
 15. Acombination according to claim 10 wherein said polymer tray comprisesexpanded polystyrene foam.
 16. A combination according to claim 10wherein said disk is selected from the group consisting of acrylic,nylon, polyethylene, polypropylene, polystyrene, polyvinyl chloride,PTFE, polyester, polycarbonate, polyurethane and acrylolnitrilebutadiene styrene.
 17. A method of building a tiled floor with a draincomprising: positioning a substantially planar shower tray bondingelement that defines a drain opening over a drain cutout in a flooringsubstrate; mortaring the planer shower tray bonding element in positionover the drain opening cutout; and positioning a polymer foam showertray on the same flooring substrate and in surrounding relationship tothe perimeter of the planer shower tray bonding element.
 18. A method ofbuilding a tiled floor according to claim 17 and further comprisingmortaring the bonding element in position using thin set mortar.
 19. Amethod of building a tiled floor according to claim 18 and furthercomprising mortaring the shower tray in position using thin set mortar.20. A method of building a tiled floor according to claim 19 and furthercomprising inserting a drain bond flange fixture into the drain cutoutand over the planar bonding element with portions of the bond flangefixture overlying portions of the planar bonding element surrounding thedrain cutout in the flooring substrate.
 21. A method of building a tiledfloor according to claim 20 and further comprising laying a tile floorover the foam tray and portions of the bond flange fixture.
 22. A methodof building a tiled floor according to claim 21 comprising adding awaterproofing membrane over the foam tray before laying the tile floor.23. A method according to claim 19 comprising connecting the drain bondflange fixture to a drain pipe below the flooring substrate.